This invention relates to a radiation detection element for radiation detectors which can prevent a possible burn-out of signal electrode wires.
In X-ray tomographing apparatus, a radiation detector is used in which in order to detect an amount of X-ray passed through, for example, the body of a human being (a subject) a plurality of radiation detection elements are regularly arranged and, for example, a xenon gas is sealed. In use, a high voltage of, for example, about 1500 volts is applied to each detector element and the xenon gas is ionized upon the entry of an X-ray. The extent of ionization of xenon gases corresponds to an amount of incident X-ray and thus the intensity of X-rays is detected by measuring ion current corresponding to an amount of variation of incident X-rays.
One of such known detection element comprises a substantially U-shaped insulating synthetic resin base frame incorporated with, for example, glass fibers and having a pair of leg portions, an electroconductive member, for example, a copper foil attached to each of the leg portions of the base frame, a plurality of fine, signal electrode wires soldered to the copper foil such that they are spanned between the leg portions of the base frame, an opposite electrode plate disposed on the rear surface of the base frame such that is confronts the signal electrode wires, and a support insulating member for supporting the opposite electrode plate.
In use, a high voltage of about 1500 volts is applied between the signal electrode wires and the opposite electrode plate of the detection element. At this time, an electric field tends to be intensified in those portions of the wires closer to the leg portions of the base frame. For this reason and because the signal electrode wires are relatively thin, a discharge tends to occur in the neighborhood of the leg portion, providing a cause for a possible burn-out of the wires.